Strap tensioning tool



March 24, 1964 o. DERRICKSON 3,125,907

STRAP TENSIONING TOOL Filed May 18, 1962 United States Patent 3,125,907 STRAP TENSIONING TOOL Michael 0. Derrickson, Nor-wood, Pm, assignor, by inesne assignments, to FMC Corporation, San Jose, Callf., a corporation of Delaware Filed May 18, 1962, Ser. No. 195,914 1 Claim. (Cl. 813) This invention relates to strap tensioning tools and more particularly to tools for facilitating the manual tensioning of a fiat, non-metallic strap about one or more articles.

It is common practice to provide containers, packages, bales and the like with tightly encircling straps or hands to reinforce them during shipment or to serve as the means for holding them closed. Such straps are also used to hold a plurality of relatively small packages together in what is known as a unitized bundle. Until recently, the straps were generally made of steel but at the present time various types of non-metallic straps are being widely used. The non-metallic straps are made of various materials and take various structural forms but insofar as the present invention is concerned the important characteristic of such straps as distinguished from steel straps, is their greater flexibility and the resultant fact that they may be bent sharply upon themselves without permanent deformation. Steel straps are generally held in position by means of a deformed seal or sleeve which engages overlapping portions of the strap. Non-metallic straps are also frequently secured in this manner but because of the greater flexibility they may be effectively secured by a buckle such as shown for example in the patent to Derrickson, No. 3,014,256. When employing the deformed seal method of securing the strap, it is of course necessary to tighten or tension the strap to the desired extent before applying the seal but when a suitable buckle is used the strap may be engaged with the buckle and then merely drawn tight, the buckle operating to hold the strap tight after the tensioning force is removed. As will become apparent, the present invention is directed to a tensioning tool which is primarily intended for use in tensioning non-metallic straps which are held in tensioned condition by a buckle.

It is an object of the present invention to provide a strap tensioning tool which may be quickly and easily engaged in a non-slipping manner with a non-metallic strap and which has a portion adapted to be engaged by a body member, i.e. hand or foot, of an operator whereby the tool is interposed between the strap and the operator so as to facilitate manual tensioning of the strap.

A further object of the invention is to provide a tensioning tool of the type referred to above which is inexpensive to manufacture, requires no repair and is characterized by an absence of moving parts.

Other objects, features and advantages of the invention will become apparent as the description of certain preferred embodiments thereof proceeds.

Referring now to the drawing:

FIG. 1 is a front elevational view of an embodiment of the tool primarily intended to be operated by foot;

FIG. 2 is a perspective view showing the manner of engaging the tool with a strap;

FIG. 3 is a side elevational view showing the tool in use;

FIG. 4 is a front elevational view of a modified embodiment of a tool primarily intended to be operated by hand; and

FIG. 5 is a side elevational view of the modified embodiment.

Referring first to that embodiment of the invention shown in FIGS. 1, 2, and 3, the tool comprises strap 3,125,907 Patented Mar. 24, 1964 engaging means in the form of a pair of parallel, spaced elements or arms 10 and 11 connected by an element 12 to an operating device consisting of a pair of arms 13 and 14. The tool is formed of a single piece of bar stock which is preferably cylindrical in cross-section and, as indicated at 15, the arm 14 may be welded to that run of the stock which forms element 12. As will be seen from FIG. 3, the various elements of the tool lie in a common plane;v in other words, the various bends shown in FIG. 1 may be considered as lying in the plane of the paper. For a reason presently to be explained, the transverse center lines of strap engaging elements 10 and 11 are in substantially a common plane with the transverse center line of the operating device comprising arms 13 and 14, such common plane being indicated in FIG. 1 at 16.

The tool thus far described is primarily intended for facilitating the application of a large tensioning force to a non-metallic strap which encircles a large object such as a bale and which is to be held in tensioned condition by a buckle preferably of general type described in the above referred to Derrickson patent. In FIG. 3, the bale or other large object is indicated at 17 and rests upon a suitable support 18 in such manner that one side thereof overhangs the edge of the support.

In strapping the object, a length of non-metallic strapping material 19 is withdrawn from a roll or other supply 20 and laced about the object. The free end of the strap is engaged with one side of a suitable buckle 21 and an intermediate portion of the strap is engaged with the other side of the buckle. As explained in the aforementioned Derrickson patent, the strap may be tightened about the article by pulling on it between the buckle and the supply 20 and when the tightening or tensioning force is released, the buckle will hold the strap taut about the article.

The manner in which the tool is associated with the strap is illustrated in FIG. 2, and will now be described. Enough strap is first withdrawn from the roll so that the strap is slack between the roll and buckle 21 and the slack portion is then folded upon itself so as to provide a loop 22 and a double loop 23. The operator then inserts the strap engaging elements of the tool into the two loops of the strap so that element 10 extends through loop 22 and element 11 through the double loop 23. This is accomplished by first moving both arms 10 and 11 to the left through double loop 23 and then moving the tool to the right so that the free end of arm 10 enters loop 22. Then by pulling on either that portion of the strap extending toward the supply or that portion extending toward the buckle or both, loops 22 and 23 are drawn into engagement with arms 10 and 11 respectively, in much the manner indicated in FIG. 3. This looped arrangement of the strap about the strap engaging arms of the tool effectively snubs the strap and prevents it from sliding about the arms when a force is exerted upon the operating portion of the tool. The tool may now be released and it will hang down from the strap in the manner of a stirrup with arms 13 and 14 extending horizontally. This balanced condition of the tool is brought about by the fact that the tool is substantially balanced about center line 16 and with the strap engaged With arms 10 and 11 the center line of the strap will lie naturally in the vicinity of center line 16. As illustrated in FIG. 3, the operator may then place his foot on the arm 14 and by pressing down exert considerable force upon the strap to draw it quite tight about the bale or the like 17. Since, as previously mentioned, the non-metallic strap is quite fleixble, the tool is readily disengaged therefrom after the tightening operation.

That form of the tool shown in FIGS. 4 and 5 is quite similar except that it is intended to be operated by hand rather than by foot. This form of tool is likewise made of a single piece of bar stock shaped to provide a pair of strap engaging elements or arms 25 and 26 spaced from which by means of a run of the stock 27 is an operating device or handle comprising upper and lower elements 28 and 29. As shown in FIG. 5, the various elements of the tool lie in a common plane and the tool is substantially balanced about a transverse center line 30, see FIG. 4, which extends approximately through the transverse centers of the strap engaging elements and the operating handle. This form of the tool is engaged with the strap in exactly the same manner as the tool shown in FIGS. 1-3 but the operator employs his hand instead of his foot for tensioning the strap. In grasping the tool, the run of stock 27 will extend between the two middle fingers. The operator is able to exert considerably more force upon the strap than he could without the use of the tool because in the latter case, a hard pull would cause the strap to pinch or otherwise hurt his hand. Also, the tool makes it convenient for the operator to either exert only a steady pull or to employ a series of quick jerks for tightening the strap. This particular embodiment of the tool is made of lighter stock than the tool shown in FIGS. 1-3 and by joining the run 27 to the center of the operating arm, rather than at one end, the operator is prevented from using his foot for leverage, which might result in bending the tool or in breaking the strap since this form is also intended for use with lighter and weaker strap.

Having thus described certain preferred embodiments of the tool, what is claimed is:

A tool for exerting a pull on a strap to tighten the strap about an article, said tool being formed of a single piece of bar stock, said stock being bent to provide first and second parallel arms adapted to be snubbingly engaged with a strap, said first arm having a free end adapted to be inserted through a loop of the strap, the bar stock extending in the plane of said arms angularly from one end of said second arm in the direction away from said first arm and terminating in a flat loop, said fiat loop constittuing an operating device by means of which the tool may be employed for exerting a pull on a strap engaged with said arms, said flat loop having a major axis extending parallel to said arms, the major axis of said fiat loop being removed from said second arm a distance greater than the distance between said arms, and said flat loop having a minor axis aligned with the transverse center line of said arms.

References Cited in the file of this patent UNITED STATES PATENTS 1,173,026 Petermann Feb. 22, 1916 1,296,205 Monneuse Mar. 4, 1919 1,375,088 Fries Apr. 19, 1921 2,154,762 McGregor et al Apr. 18, 1939 2,311,063 Martin Feb. 16, 1943 

